Apparatus for piecing a thread in an open-end spinning unit

ABSTRACT

Apparatus for piecing a thread end in an open-end spinning unit which includes a clamping device having clamping members for clamping the thread end therebetween and means for moving the clamping members in a direction transverse to the longitudinal direction of the thread end while said thread end is clamped so as to effect at least a partial elimination of the spinning twist in the thread end. A gripping device is provided which is spaced from the clamping device for gripping the thread end and for accommodating insertion of the thread end, after the elimination of the spinning twist, into a spinning turbine containing a ring of open-up fibers to which the end is to be joined. Various preferred embodiments of clamping members are disclosed, including endless belts having runs in opposition to one another, cylindrical surface clamping members, and planar surface clamping members. A suction nozzle is provided for holding the thread end in position for the clamping and gripping operations and for removing a separated portion of the thread end prior to insertion of the thread end into the spinning turbine rotor.

United States Patent Stahlecker et al.

[ Dec. 16, 1975 APPARATUS FOR PIECING A THREAD IN AN OPEN-END SPINNINGUNIT [76] Inventors: Fritz Stahlecker,

Josef-neidhart-Strasse 18, D 7341 Bad Ueberkingen; Hans Stahlecker,Haldenstrasse 20, D 7334 Suessen, both of Germany [22] Filed: Oct. 10,1974 [21] Appl. No.: 513,775

[30] Foreign Application Priority Data Oct. 10, 1973 Germany 2350844[52] US. Cl. 57/34 R; 57/58.89 [51] Int. C13. DOIH 7/00; D01H 1/12; DOIH15/00 [58] Field of Search i. 57/22, 34 R, 34 'IT, 58.89, 57/58.95, 81,83, 159

[56] References Cited UNITED STATES PATENTS 2,515,172 7/1950 Abbott57/159 3,163,976 l/1965 Juillard 57/58.89 3,425,205 2/1969 Landwehrkampet al. 57/58.89 3,492,804 2/1970 Landwehrkamp et al..... 57/58.89 X3,626,440 12/1971 Harmon 57/34 R 3,722.]98 3/1973 Gotzfried 57/58.89

Primary Examiner-Donald E. Watkins Attorney, Agent, or Firm-Craig &Antonelli [5 7 ABSTRACT Apparatus for piecing a thread end in anopen-end spinning unit which includes a clamping device having clampingmembers for clamping the thread end therebetween and means for movingthe clamping members in a direction transverse to the longitudinaldirection of the thread end while said thread end is clamped so as toeffect at least a partial elimination of the spinning twist in thethread end. A gripping device is provided which is spaced from theclamping device for gripping the thread end and for accommodatinginsertion of the thread end, after the elimination of the spinningtwist, into a spinning turbine containing a ring of open-up fibers towhich the end is to be joined. Various preferred embodiments of clampingmembers are disclosed, including endless belts having runs in oppositionto one another, cylindrical surface clamping members, and planar surfaceclamping members. A suction nozzle is provided for holding the threadend in position for the clamping and gripping operations and forremoving a separated portion of the thread end prior to insertion of thethread end into the spinning turbine rotor.

20 Claims, 8 Drawing Figures U.S. Patent Dec. 16, 1975 Sheet 1 of23,925,975

F ig.1

Fig 2 32 34 5 34(1/10 33 5 35 Fig.3 32 34 34 10 33 5 35 5c Figl. 32 34 54/ US. Patent Dec. 16, 1975 Sheet 2 of2 3,925,975

APPARATUS FOR PIECING A THREAD IN AN OPEN-END SPINNING UNIT BACKGROUNDAND SUMMARY OF THE INVENTION This invention relates to an apparatus forpiecing a thread in an open-end spinning unit with a device forreturning the thread end into a spinning rotor containing a ring ofopened-up fibers and with a means for the at least partial eliminationof the spinning twist in the thread end being returned. Relatedapplications of applicants to be filed herewith, having similar titlesas the present application, and based on US. Application Ser. Nos.513,776 and 513,849, both filed on even date herewith are incorporatedherein to the extent necessary for a complete understanding of thepresent invention.

To obtain piecing zones without reduced tear strength and withoutthickened portions or the like, it has been proposed to open up the endof the thread by reversing the spinning rotation so that the threadcondition corresponds approximately to that of the fiber ring depositedin the spinning rotor. This produces a substantial simplification of thepiecing step, furthermore leading to improved yarn qualities at thepiecing zone.

This invention is based on the problem of providing an apparatus of theaforementioned type with structurally simple means, yet affording a highfunctional safety. The invention contemplates providing a clamp ingmeans which is arranged for receiving the thread end, this clampingmeans having two mutually opposed clamping surfaces, at least one ofwhich is drivable to move at right angles to the longitudinal directionof the thread. With the aid of this device, it is possible to untwistand open up the thread end by a mutual displacement of the clampingsurfaces, so the thread end is prepared for a piecing step. i

In order to limit the opening of the thread end to a certain zone, thepresent invention further contemplates providing an insert or grippingdevice for the thread located at a spacing from the clamping means incloser proximity to the windup mechanism than the clamping means. Sincethe zone of the thread between the clamping means and the insert deviceis opened up particularly well, the present invention furthercontemplates arranging a separator for the thread between the clampingmeans and the insert device. This separator includes means to cut offthe thread end in this zone, so that a definitely very well opened upthread end can be introduced into the spinning rotor. For the samepurpose, another embodiment of the invention furthermore provides thatthe clamping means and/or the insert device are arranged to be movablewith respect to each other in the longitudinal direction of the thread.Thereby, the opened up thread can be torn apart in this zone, wherebythe opening procedure is still further improved.

These and further objects, features and advantages of the presentinvention will become more obvious from the following description whentaken in connection with the accompanying drawings which show, forpurposes of illustration only, several embodiments in accordance withthe present invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of anapparatus constructed according to the invention;

FIGS. 2 to 4 are enlarged partial schematic views showing details of aclamp forming part of the apparatus according to FIG. 1 in variousoperating positions;

FIG. 5 is a view schematically depicting a preferred embodiment of theinvention for operating the clamp of FIGS. 2 to 4;

FIG. 6 is a view schematically depicting a further preferred embodimentof the invention for operating the clamp of FIGS. 2 to 4;

FIG. 7 is a view schematically depicting another embodiment of a clampconstructed in accordance with the present invention; and

FIG. 8 schematically shows another embodiment of the clamping deviceintended for opening up the end of the thread in accordance with thepresent invention.

DETAILED DESCRIPTION OF THE DRAWINGS FIG. 1 shows only the zone of aspinning rotor 2 of an open-end spinning unit 1 wherein, via feeding andopening means, not shown, a ring 3 of opened up fibers is continuouslydeposited during operation. This ring 3 is normally withdrawn as a spunthread by way of a yarn takeofi duct 4 and, during normal operation, iswound up on a windup spool 8, in a manner not shown in detail, with theaid of a windup roll 6. Since constructions are known in the prior artfor feeding and opening a supply of material to the spinning rotor 2, aswell as for taking off and winding up the finished yarn, certain detailsthereof have not been included herein in order not to obscure thepresent invention.

In case of a thread breakage or when the spinning machine is put intooperation after being stopped, the thread 5 is withdrawn from the windupspool 8 and returned into the spinning rotor 2 via the yarn takeoff duct4. This return operation is controlled by a device not shown in detailin FIG. 1, of which FIG. 1 illustrates only an auxiliary windup roll 7which, during the return and piecing operations, drives the windup spool8 so that first the thread 5 is unwound and thereafter is wound upagain. Details of means for carrying out the return operation which arenot included herein can be found in prior art constructions, andtherefore the same have been dispensed with herein in order not toobscure the present invention.

Before the thread end is returned into the spinning rotor 2 via the yarntakeoff duct 4, the thread end is opened up so that its condition ismaximally close to that of the fiber ring 3. For this purpose, aclamping means 10 is provided, in the zone of which the thread 5 is heldwith the aid of a suction nozzle 9. The clamping means 10 is arranged ona swivel arm 11 pivotable about a shaft 12. An insert or grippingmechanism 13 is arranged between the windup spool 8 and the clampingmeans 10, which limits the opening of the thread 5 to the zone betweenthe clamping means 10 and the insert mechanism 13. The insert mechanism13 is also disposed on a swivel arm 14 which can be swung, about a pivotaxle 15, into the position 13 shown in dashed lines so that the insertmechanism 13 can bring the thread end into the zone of the mouth of theyarn takeoff duct 4; the thread end can then be sucked by vacuum viathis duct 4 into the spinning rotor 2. I

After the thread end has been opened up by untwisting same against itsrotary spinning twist, the thread end 5 is advantageously severed in thearea between the clamping means 10 and the insert device 13, so thatthis separating point 5a is then placed into contact with the fiber ring3 in the spinning rotor 2 for piecing purposes.

In order to make do without an additioial separating mechanism, it iscontemplated to provide a swivel drive for the swivel arm 11, pivotingthe latter together with the clamping means 10 in the direction of arrow17 (arrow 18 depicting a return direction). Thereby, the already openedup thread can be torn apart which, due to a stretching action within thethread end, results in an even more improved opening effect.

FIGS. 2-4 show the function of one embodiment of the clamping means in aschematic view. The clamping means 10 includes two clamping jaw guides32 and 33 receiving clamping jaws 34 and 35 which are coated on theirmutually facing surfaces 343 and 35a for example with a friction coatingof a synthetic resin or the like, ensuring satisfactory entrainment. Theclamping jaws 34 and 35 are opened manually or mechanically (FIG. 2,arrows 36, 37 depicting opening and closing movements) so that thethread end 5 can be inserted therebetween. Subsequently, the clampingjaws 34 and 35 are closed again and clamp the thread end 5 therebetween(FIG. 3). Then, the clamping jaws 34 and 35 are shifted in thedirections of arrows 39 and 40 in mutually opposite directions and atright angles to the longitudinal direction of the thread, so that thethread 5 is turned (FIG. 4). In this connection, it is advantageous todisplace both clamping jaws with respect to each other, since in such acase the thread 5 does not change its position and is merely untwisted.After the untwisting, the thread is severed in the manner describedabove in relation to FIG. 1, whereupon the remainder 5b initiallyremaining in the clamping means 10 can be removed after opening of theclamping jaws 34 and 35 by suction with the aid of the suction nozzle 9.The thread end 5c to be pieced is then fed to the yarn take off duct 4;see the extension of the thread 5c and 5d shown in dot-dash lines.

FIG. 5 shows a preferred embodiment for operating clamping means 10. Inthis embodiment, the upper clamping jaw 34 is attached with a bracket 41(corresponding to jaw guide 32 of FIG. 2) to a guide element 43 so thatit is movable about an axle 42. The guide element 43 is disposed movablyon a guide rod 49 (movement directions depicted by arrows 60, 61) and,by means of a locking device 50, fixedly on a guide rod 48 disposed inparallel to rod 49. The guide rod 49 is fixedly joined to a guideelement 46 for the lower clamping jaw 35 with the aid of a lockingdevice 51, while the guide rod 48 is movably guided in element 46. Theguide element 46 has a sliding guide for a holding member 44(corresponding to jaw guide 33 of FIG. 2) of the lower clamping jaw. Theholding member 44 is operated by way of a tension cable 62 guided via aguide roller 63 to a pulley 69 connected to a small electric motor 70operable in one direction. The holding member 44 is furthermoresupported by means of a compression spring 47 attached at 64 by which itis held in the initial position illustrated in FIG. 5. From thisposition, the holding member can be moved by the traction cable 62 androtor 70 in the direction of arrow 67, with return via spring forces indirection of arrow 68. The extent to which the thread is untwisted canbe determined by the appropriate control of the displacement path of theclamping jaw 35. To provide adjustability for this feature, anadjustable stop 45 is provided for the holder 44 of this clamping jaw35, by means of which the initial position of the clamping jaw 35 ispre- 4 determined. Arrows 65 and 66 indicate the direction of movementof traction cable 62.

The sliding bar 48 guided movably in the guide element 46 is supported,by way of a coupling member 55, at a piston 56 of a solenoid (liftingmagnet) 57 controlling the opening and closing of the clamping jaws 34and 35 (arrows 58 and 59depict movement of piston 56). The sliding bar48 is stressed by a compression spring 52 arranged between a disk 53,attached to the bar, and the guide element 46 so that the clamping jaw34 assumes the closed position if the piston 56 of the solenoid 57 islowered.

The sliding bars 48 and 49 terminate in a holder 54 and form, togetherwith the latter, swivel arm 11 pivotable about an axle 12 in accordancewith FIG. 1. The holder 54 is provided with a gear wheel 71 flangedthereto and engaging a pinion, not shown in detail, which effects thepivoting motion to tear apart the thread end 5.

In the embodiment of FIG. 6, showing another form of the clamping means10, the upper clamping jaw 34 is held at the guide element 43 with aparallelogram suspension. Via a hinged coupling means 83, an adjustingmember 84 is joined thereto; by means of this adjusting member, theupper jaw 34 can be displaced with respect to the lower jaw 35. Duringthis step, the guides 76 and 77 are pivoted about the axles 78, 79, 80,and 81. Members and 82 support these axles as shown. Arrows 85-86 depictdirections of movement of jaw 34. Lower jaw 35 is supported by member74.

In the embodiment of clamping means illustrated in FIG. 7, the lowerclamping jaw 87 is provided with a trough-like clamping surface. Theupper clamping jaw 88 has the shape of a cylinder, the axis of whichextends in the direction of the thread. The clamping jaw 88 havingcorrespondingly a cylindrical clamping surface 89 is driven in a mannernot shown in detail so that the thread end is freed of its spinningtwist. This clamping jaw is mounted to a lever 91 pivotable about itsaxle 92 and held in the illustrated position by means of a compressionspring 93. To insertthe thread, the cylindrical clamping jaw 88 can belifted with the aid of a solenoid 94 engaging the lever 91. Arrows 95,96 depict directions of movement of the piston of solenoid 94.

As is furthermore illustrated in FIG. 8, it is contemplated to providealso small belts 97 and 98 as the clamping surfaces; these belts areguided around driven and non-driven rollers 99, 100, 101, and 102 sothat the mutually opposed zones execute a double motion in accordancewith the arrows 103 and 104, and consequently the thread end 5 disposedtherebetween can be untwisted. The rollers of one of the small belts 97or 98 are disposed on a holder movable with respect to the other parts,so that the mutual spacing of the belts 97 and 98 can be opened up toinsert the thread 5.

While we have shown and described several embodiments in accordance withthe present invention, it is understood that the same is not limitedthereto but is susceptible of numerous changes and modifications asknown to those skilled in the art and we therefore do not wish to belimited to the details shown and described herein but intend to coverall such changes and modifications as are encompassed by the scope ofthe appended claims.

We claim:

1. Apparatus for piecing a thread end in an open-end spinning unithaving a spinning rotor with a ring of opened-up fibers comprising:

a clamping device containing a first clamping member, and a secondclamping member,

first clamp control means for moving said clamping members toward andaway from one another to effect clamping and unclamping of a portion ofsaid thread end therebetween,

second clamp control means for moving said clamping members with respectto one another in a direction transverse to the longitudinal directionof said portion of said thread end while said portion of said thread endis clamped between said clamping members to effect at least partialelimination of the spinning twist in said thread end,

and a device for returning the thread end into the spinning rotor aftersaid partial elimination of the spinning twist.

2. Apparatus according to claim 1, wherein a gripping device is providedfor gripping said thread end at a spacing from the portion of saidthread end clamped by said clamping members.

3. Apparatus according to claim 2, wherein said spinning unit includes awindup mechanism for winding up the thread containing said thread end,and wherein said gripping device is disposed closer to said windupmechanism than are said clamping members.

4. Apparatus according to claim 3, wherein a separating device forseparating the thread is arranged between the clamping members and thegripping device.

5. Apparatus according to claim 3, wherein means are provided for movingsaid clamping device and gripping device with respect to one another inthe longitudinal direction of said thread end.

6. Apparatus according to claim 3, wherein at least one of said clampingdevice and said gripping device are mounted on a pivotally mountedswivel arm for accommodating relative movement of said clamping deviceand gripping device.

7. Apparatus according to claim 5, wherein at least one of said clampingdevice and said gripping device are mounted on a pivotally mountedswivel arm for accommodating relative movement of said clamping deviceand gripping device.

8. Apparatus according to claim 1, wherein a suction nozzle is providedfor holding said thread end in a position to accommodate clampingthereof by said clamping device.

9. Apparatus according to claim 7, wherein a suction nozzle is providedfor holding said thread end in a position to accommodate clampingthereof by said clamping device.

10. Apparatus according to claim 1, wherein at least one clampingsurface of said clamping member is coated with a friction coating.

11. Apparatus according to claim 10, wherein said friction coatingincludes synthetic resinous material.

12. Apparatus according to claim 1, wherein at least one of saidclamping members has a cylindrical shaped clamping surface forclampingly engaging said thread end portion.

13. Apparatus according to claim 7, wherein at least one of saidclamping members has a cylindrical shaped clamping surface forclampingly engaging said thread end portion.

14. Apparatus according to claim 1, wherein at least one of saidclamping members includes a movable belt with a Clamping surface formedthereon, and wherein said second clamp control means includes means formoving said belt in a direction at right angles to said longitudinaldirection of said thread end.

15. Apparatus according to claim 1, wherein each of said clampingmembers are formed as endless belts with clamping surfaces formedthereon, and wherein said second clamp control means includes means formoving said belts in mutually opposite directions with said thread endportion clamped between opposing faces of said belts.

16. Apparatus according to claim 1, wherein one of said clamping membersis supported by a pair of parallel rods pivotally mounted at both theclamping member and a further support member.

17. Apparatus according to claim 12, wherein said second clamp controlmeans includes means for rotating one of said clamping members.

18. Apparatus according to claim 1, wherein said first clamp controlmeans includes a solenoid operated lever attached for movement with saidfirst clamping members.

19. Apparatus according to claim 18, wherein said second clamp controlmeans includes a tension cable attached to and movable with said secondclamping member.

20. Apparatus according to claim 3, wherein said separating deviceincludes means for forcibly pivoting a swivel arm supporting saidclamping device so that said thread end is separated intermediate saidgripping and clamping device while being clamped by said clamping deviceand gripped by said gripping device.

1. Apparatus for piecing a thread end in an open-end spinning unithaving a spinning rotor with a ring of opened-up fibers comprising: aclamping device containing a first clamping member, and a secondclamping member, first clamp control means for moving said clampingmembers toward and away from one another to effect clamping andunclamping of a portion of said thread end therebetween, second clampcontrol means for moving said clamping members with respect to oneanother in a direction transverse to the longitudinal direction of saidportion of said thread end while said portioN of said thread end isclamped between said clamping members to effect at least partialelimination of the spinning twist in said thread end, and a device forreturning the thread end into the spinning rotor after said partialelimination of the spinning twist.
 2. Apparatus according to claim 1,wherein a gripping device is provided for gripping said thread end at aspacing from the portion of said thread end clamped by said clampingmembers.
 3. Apparatus according to claim 2, wherein said spinning unitincludes a windup mechanism for winding up the thread containing saidthread end, and wherein said gripping device is disposed closer to saidwindup mechanism than are said clamping members.
 4. Apparatus accordingto claim 3, wherein a separating device for separating the thread isarranged between the clamping members and the gripping device. 5.Apparatus according to claim 3, wherein means are provided for movingsaid clamping device and gripping device with respect to one another inthe longitudinal direction of said thread end.
 6. Apparatus according toclaim 3, wherein at least one of said clamping device and said grippingdevice are mounted on a pivotally mounted swivel arm for accommodatingrelative movement of said clamping device and gripping device. 7.Apparatus according to claim 5, wherein at least one of said clampingdevice and said gripping device are mounted on a pivotally mountedswivel arm for accommodating relative movement of said clamping deviceand gripping device.
 8. Apparatus according to claim 1, wherein asuction nozzle is provided for holding said thread end in a position toaccommodate clamping thereof by said clamping device.
 9. Apparatusaccording to claim 7, wherein a suction nozzle is provided for holdingsaid thread end in a position to accommodate clamping thereof by saidclamping device.
 10. Apparatus according to claim 1, wherein at leastone clamping surface of said clamping member is coated with a frictioncoating.
 11. Apparatus according to claim 10, wherein said frictioncoating includes synthetic resinous material.
 12. Apparatus according toclaim 1, wherein at least one of said clamping members has a cylindricalshaped clamping surface for clampingly engaging said thread end portion.13. Apparatus according to claim 7, wherein at least one of saidclamping members has a cylindrical shaped clamping surface forclampingly engaging said thread end portion.
 14. Apparatus according toclaim 1, wherein at least one of said clamping members includes amovable belt with a clamping surface formed thereon, and wherein saidsecond clamp control means includes means for moving said belt in adirection at right angles to said longitudinal direction of said threadend.
 15. Apparatus according to claim 1, wherein each of said clampingmembers are formed as endless belts with clamping surfaces formedthereon, and wherein said second clamp control means includes means formoving said belts in mutually opposite directions with said thread endportion clamped between opposing faces of said belts.
 16. Apparatusaccording to claim 1, wherein one of said clamping members is supportedby a pair of parallel rods pivotally mounted at both the clamping memberand a further support member.
 17. Apparatus according to claim 12,wherein said second clamp control means includes means for rotating oneof said clamping members.
 18. Apparatus according to claim 1, whereinsaid first clamp control means includes a solenoid operated leverattached for movement with said first clamping members.
 19. Apparatusaccording to claim 18, wherein said second clamp control means includesa tension cable attached to and movable with said second clampingmember.
 20. Apparatus according to claim 3, wherein said separatingdevice includes means for forcibly pivoting a swivel arm supporting saidclamping device so that said thread end is separated intermediate saidgripping and clamping device while being clamped by said cLamping deviceand gripped by said gripping device.